1. Field of the Invention
The present invention relates to a liquid pressure type steering damper system for vehicles which is preferable for saddle ride type vehicles such as motorcycles and the like and is used for restraining the swing of a handle during operation.
2. Description of Background Art
In order to prevent the handle from being swung due to a kick-back upon a disturbance, liquid pressure type steering damper systems which generate a damping force against the swing have been known, for example, as disclosed in Japanese Patent No. 2593461. In addition, systems in which the damping force is variable so that the damping force is generated only when required and a needless damping force is not generated in other situations have also been known; for example, a system which controls the damping force based on steering angle and operating velocity as disclosed in Japanese Patent Laid-open No. Sho 63-64888. In addition, a system which controls the damping force based on variations in the load on the front wheel is disclosed in Japanese Patent Publication No. Hei 7-74023.
Further, the regulation of the damping force in the above-mentioned related art examples is only to generate the damping force correspondingly to the magnitude of the kick-back forecasted to be generated. It is considered that the generation of the damping force is controlled so as to be linear in proportion to a variable quantity (corresponding to steering angle, operating velocity and load on the front wheel, in the above-mentioned related art examples) related to the magnitude of the kick-back. However, there are some cases where in order to make steerability more satisfactory in conformity with the actual operation, it is desirable to correct the damping force which varies linearly (hereinafter this damping force will be referred to as reference value), according to the magnitude of the kick-back forecasted. Moreover, such a correction must be based on a variable quantity which has a close relationship with the magnitude of the kick-back forecasted and with which the steering conditions at the time of actual running can be grasped appropriately. Accordingly, it is an object of the present invention to realize the above-mentioned requests.